That's nice, but we've had this for a couple of decades in EditPlus. Does the Visual Studio plugin have auto-complete? Type a function name and EditPlus will auto-complete the syntax. The syntax files are user-editable, so you can keep them up-to-date.

Yeah, it's not necessarily a NEW thing, but a lot of people (including me) use or are moving to VSCode for editing.

If you click the link, you'll see the features from the change log on the extension page but more detail is in the code if you navigate to the Github page for it. Not sure how familiar you'd be with Git and Github, but you can do several things. You can create an issue for the extension author/maintainer to add certain functionality you request, you can create a pull request that allows you to make modification that can be committed to the master branch of the project after approval, or you can simply fork the project and modify it to your hearts extent on your own. Your "fork" is your own copy of the project to do what you want with.

My colleague has just released his own extension for WebFOCUS in VS Code onto the VS Marketplace. It has a TON more functionality than the other extension we used to use. Please check it out and give it a spin!